Paper box for wrapping refrigerated meat

ABSTRACT

A paper box is provided for wrapping refrigerated meats, which is characterized by a paper board for prevention of strength loss due to moisture pick-up during usage, and also for prevention of drying for good preservation and for easy separation of the meat from the box.

United States Patent [191 Kato 1451 Sept. 2, 1975 PAPER BOX FOR WRAPPING REFRIGERATED MEAT [76] Inventor: Eiji Kato, 2-1 1, Higashiteraokitadai,

Tsurumi-Ku, Yokohama, Japan [22] Filed: Nov. 13, 1973 [21] App]. No.: 415,443

[52] US. Cl 229/35 R; 206/819; 428/35; 428/81; 428/121; 428/156; 428/157;

[51] Int. Cl. B65D 1/28; B32B 3/04 [58] Field of Search 229/25, 87 R, 3.5 R; 162/112,116,117,123;161/116,l17,119

[56] References Cited UNITED STATES PATENTS 2,834,809 5/1958 Schutte et a1 162/117 3,040,948 6/1962 Wells 229/25 3,346,400 10/1967 Roesner.... 229/25 X 3,706,410 12/1972 Baker 206/527 X 3,845,896 11/1974 Crabtree 229/25 Primary Examiner-George F. Lesmes Assistant Examiner-A1an T. McDonald Attorney, Agent, or Firm-Ob1on, Fisher, Spivak, McClelland & Maier [5 7] ABSTRACT A paper box is provided for wrapping refrigerated meats, which is characterized by a paper board for prevention of strength loss due to moisture pick-up during usage, and also for prevention of drying for good preservation and for easy separation of the meat from the box.

6 Claims, 2 Drawing Figures PAPER BOX FOR WRAPPING REFRIGERATED MEAT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a paper box, and more particularly to a paper box which can be used for wrapping of refrigerated meats, and which is adapted topreferably exhaust air and moisture discharged from said wrapped meats, particularly fish, animal or chicken meat, during the period in which refrigerated meat is contained therein for preservation and transportation.

2. Description of the Prior Art Heretofore, in situations where meat has been wrapped in a paper box and then refrigerated, many problems have been noted, for example, the air and moisture normally discharged from the meat when the contents of the paper box are compressed on wrapping or packing are not sufficiently exhausted from the box. Consequently, the surface of the meat takes on a rough, irregular or cratered shape and ice tends to form and be entrapped in the meat. This seriously reduces the edibility and the value of the meat. Moreover, moisture tends to be frozen between the inner surface of the box and the meat surface so that it becomes difficult to remove from the box. Also since the box is insufficiently water proofed, the box tends to become wet and this reduces the strength of the box.

A box has recently been proposed which has fine raised patterns embossed randomly on the inner surface of the box. Since the embossed raised patterns however, are mutually independent, air and moisture tends to accumulate within the recesses of the box since it cannot be sufficiently exhausted out of the box.

SUMMARY OF THE INVENTION It is, therefore, one object of the present invention to provide a paper box for wrapping refrigerated meat which will not be subjectto reduced strength due to moisture retention.

It is another object of the present invention to provide a paper box which can be used for wrapping refrig erated meats, which box will function to dispel accumulated air and moisture as formed therein.

It is still another object of the present invention to provide a paper box for wrapping refrigerated meat which will prevent the contents from such drying as to induce spoilage and which will facilitate separation of the contents from the box after refrigeration.

In order to achieve the aforementioned and other objects, the degree of sizing of the paper of the box should be between 900 -4,200 seconds and the cobb water absorption degree thereof should be below 32 g/m The box of the present invention has better water resistance and water-proofing properties for meat wrapping purposes than normal paper board since it enables water to be discharged from the meat during refrigeration and subsequent melting. The cobb water absorption degree is preferably below 25 g/m The aforementioned sizing degree is obtained from test measurements according to JIS P-8l22, and the cobb water absorption degree is obtained from test measurements according to JIS P-8140. The thickness of the paper should be /100 65/100 mm in order to maintain the bursting strength within the range of 3.5 -14 kg/cm after embossing. The upper range is limited only byeconomic necessities and the lower range is determined by the 'pre-determined necessary strength. The degree of sizing of the paper box material is thus greater than normal paper board, since the strength of the paper box must be such to prevent abrupt deterioration when the box becomes moistened during usage. The bursting strength of the paper box is thus selected as indicated above so that when the box and contents are under the stress of packing, differential cracking will appear in the waterproof coating. That is, when the waterproofed coating paper is under stress it will be so altered that a large differential in air permeability will occur as between the uneven or embossed portions and the normal areas. This results in the accumulated air and moisture being gradually displaced through the paper plys and out of the box. Such cracking at the embossed portions is very fine and may be either visible or invisible. Cracks may also be formed when the rugose portions are embossed since when the paper is tensioned some paper fibers will be broken. These will occur however, mainly in the waterproof coating when the paper box contents are under stress.

As discussed above, the bursting strength of the paper box must be maintained within 3.5-]4 kg/cm after embossing in terms of Mullen bursting strength as defined by JIS P-813l, preferably 3.512.5 kg/cm If the bursting strength of the paper box is greater than 14 kg/cm it becomes impossible for the air and moisture to be discharged from the box with the result that refrigeration will produce ice throughout the meat in the paper box..This results in greatly reducing the commercial value of the packed article. The cobb water absorption degree of the paper box is indicated as being below 32 g/m so that the moisture may gradually disperse or be absorbed into the paper of the box.

The paper box of the present invention has another feature in that the rugose patterns are embossed randomly so that recessed grooves for communication between the rugose patterns are formed in order to facilitate discharge of the air and water produced when the meat is wrapped in the paper box. The box of the present invention is shown in FIG. 1, in which the fold lines and the partially folded structure can be seen. FIG. 2 is a fragmentary prospective view showing the rugose surfaces of the box.

The shape of the rugose patterns embossed on the paper of the box of the present invention is not critical. Preferably, they are semi-elliptic or spherical recesses formed in such a manner that the length of one side is l-8mm, the intervals between the recesses are 0.58mm, the density of the recesses is 2-1 l/cm the angle of the recess with respect to the surface of the paper board of the box is l045, its depth is 40-1 30% of the thickness of the paper, preferably l 10%, and the recesses are so arranged as to be in a zig-zag form such that the recessed side will be on the inside of the box. If the depth of the recesses are less than 40% of the thickness of the paper, the recesses will not function to permit sufficient discharge of the air and moisture from the paper box. If they are over the paper board of the box will he so penetrated by the recesses as to lose the intended function of the recesses, because if there are fine penetrated holes throughout the paper board of the box, which are caused by excessive recessing, the moisture initially discharged from the content in the paper box is frozen therein which will prevent discharge of subsequently formed air and moisture.

Further, if the angle of the recesses with respect to the surface of thepaper board of the box is less than the recesses cannot function properly to form the desired cracking in the waterproof coating of. the rugosepatterns of the paper board of the box when under the tension present during the wrapping of the meat. There would thus be lacking the fine cracking necessary to permit air and water discharge as described above. On the other hand, if the acute angle thereof is over 45, the paperboard of the box will be broken when embossed so as not to possess the necessary strength in the form of a paper box.

If the intervals between the recesses are over 8mm or the density of the recesses is less than 2/cm the distribution of the water proof coating of the rugose portions of the paper box becomes excessively uneven so that the air and moisture cannot be sufficiently discharged from the paper box. This results in the formation of foaming and stripe scarring on the surface of the .contents. On the other hand, if the intervals between the recesses are less than 0.5mm, or the density thereof is over ll/cm the strength of the paper box will be so weakened that compression of the contents in the paper box on wrapping becomes difficult. In addition, if the length of one side of the recesses is less than 1mm, it is difficult to obtain recesses having the aforementioned necessary depth omitted if the length thereof is over 8mm, the cracks formed per recess is far below what is required.

The paper box of the present invention has still another feature namely that recessed grooves of 3/100 65/100 mm in depth are formed linearly or nonlinearly for connecting the rugose patterns with each other as well as the portions corresponding to the upper four peripheral edges of the paper box in order to evenly and efficiently discharge from the box the air and moisture produced when meat is packed and compressed therein.

In view of the moisture produced upon refrigerating and thawing of the meat and the force applied to the paper box upon removal of the meat from the paper box for usage, the water resistance of the paper board of the box after embossing is defined as 40 350 g/m of the recessed surface and the air permeability thereof is defined as 200-4,500 sec./100cc. The air permeability is preferably 200 2,500 sec./l00cc. The above cited water resistance values are obtained from a measurement which comprises pouring water at 20C. into a ring, removing the water after 24 hours, removing the adhered water with a filter to measure the absorbed water, employing a moisture permeability cup described in JIS ZO208. The above air permeability values are obtained from the measurement test described in .IIS P8l 17. If the water resistance is less than 40 g/m at the recess surface, the moisture in the paper box cannot be sufficiently discharged from the paper box so that the paper box contents are subject to deterioration, while if the water resistance is above 350 g/m at the recess surface, an excessive amount of moisture is absorbed in the paper box weakening it excessively. The water resistance is preferably 80-260 g/m If the air permeability is less than 200 sec./l00cc, the air in the paper box is excessivey exhausted so that proper preservation and stability of the contents cannot be maintained, whereas if th air permeability is above 4,500 sec./l00cc, the air in the paper box is not suffl ciently discharged with the result that the quality of the contents is unacceptably lowered. Thus, the air permeability of the paper board of the box is preferably within 2002,500 sec./l00cc.

If the paper box is completely dehydrated, fine spaces tend to appear between the contents and the paper box with the result that the air in the spaces shift about, thus proper preservation of the box contents cannot be maintained. However, the paper box of the present invention is slightly absorbent of the moisture so as to enable close contact between the contents and the paper box whereby the air in the flat portion is exhausted thereby preventing the box contents from drying, thus maintaining proper preservation. Further, the easy separation of the contents from the paper box is facilitated.

As indicated inthe foregoing description, the paper box of the present invention can maintain the strength of the box against exposure to moisture during usage, can gradually discharge the air and moisture from the paper box for proper preservation of the contents and also can prevent the content in the box from drying, thereby maintaining proper content preservation and can facilitate easy removal of the contents from the paper box under conditions of use as described above. There is thus provided an article of great commercial and industrial value.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT The following Example is given by way of an illustration only.

EXAMPLE Both sides of a multi-ply paper board having a thickness of 50/l00mm a sizing degree of 2,200 seconds, a cobb water absorption degree of 23 g/m were coated for imparting waterproofing properties -as described above, and then semi-elliptic spherical recesses having a density of 4/cm of a side length of 2.5-4.5mm at intervals of 2mm with of the depth with respect to the thickness embossed in a zig-zag form at an angle of 20 with respect to the surface of the paper board. Fish was packed in the paper box having 1,200 sec/ cc of air permeability, g/m of water resistance at the recess surface and 10.5 kg/cm bursting strength, and thereafter compressed for 3.5 hours at 40 kg/cm of pressure during refrigeration. The contained fish was thus maintained indefinetely in a proper state of preservation for shipping and storage. The contents of the paper box were easily removed from the box for sale and use as food.

Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention I as set forth herein.

What is claimed as new and desired to be secured by letters patent of the United States is:

1. A paper box for wrapping refrigerated meat comprising single or multi-ply paper board having a thickness of 20/100 -65/l00 mm, a degree of sizing of 900 4,200 seconds, degree of cobb water absorption of less than 32 g/m which is embossed with rugose pat terns having a length of l 8mm with a depth of 40 l 30% of the thickness of the paper, at an angle of 10 45 with respect to the surface of the paper board, at intervals of 0.5 8mm and a density of 2 1 l/cm and having a water resistance of 40 350 g/m at the rugose surface, an air permeability of 200 4,500 sec./l00cc and a bursting strength after embossing of 3.5 14 kg/cm and having fine cracking in the water resisting coating at the rugose surface.

2. A paper box according to .claim 1, wherein said rugose patterns are in the form of semi-elliptic and/or spherical recesses said recesses being arranged in a zigzag manner.

3. A paper box according to claim 2 in which the peripheral edges and the rugose patterns are connected by linear to non-linear recessed grooves having a depth of from 3/100 mm to 65/100mm.

4. A paper board useful for forming a paper box for wrapping refrigerated meat which comprises: single or multi-ply paper board having a thickness of 20/100 65/100 mm, a degree of sizing of 900 4,200 seconds, degree of cobb water absorption of less than 32 g/m which is embossed with rugose patterns having a length of l 8 mm with a depth of 40 130% of the thickness of the paper, at an angle of IO 45 with respect to the surface of the paper board, at intervals of 0.5 8 mm and at a density of 2 l l/cm and having a water resistance of 40 350 g/m at the rugose surface, an air permeability of 200 4,500 sec/ cc and a bursting strength after embossing of 3.5 14 kg/cm and having fine cracking in the water resistant coating at the rugose surface.

5. The paper board of claim 4, wherein said rugose patterns are in the form of semi-elliptic and/or spherical recesses, said recesses being arranged in a zig-zag manner.

6. The paper board of claim 4, wherein the peripheral edges and the rugose patterns are connected by linear to non-linear recessed grooves having a depth of from 3/100 mm to 65/100 mm. 

1. A paper box for wrapping refrigerated meat comprising single or multi-ply paper board having a thickness of 20/100 65/100 mm, a degree of sizing of 900 - 4,200 seconds, degree of cobb water absorption of less than 32 g/m2, which is embossed with rugose patterns having a length of 1 - 8mm with a depth of 40 -130% of the thickness of the paper, at an angle of 10* - 45* with respect to the surface of the paper board, at intervals of 0.5 - 8mm and a density of 2 - 11/cm2, and having a water resistance of 40 350 g/m2 at the rugose surface, an air permeability of 200 4,500 sec./100cc and a bursting strength after embossing of 3.5 14 kg/cm2 and having fine cracking in the water resisting coating at the rugose surface.
 2. A paper box according to claim 1, wherein said rugose patterns are in the form of semi-elliptic and/or spherical recesses said recesses being arranged in a zig-zag manner.
 3. A paper box according to claim 2 in which the peripheral edges and the rugose patterns are connected by linear to non-linear recessed grooves having a depth of from 3/100 mm to 65/100mm.
 4. A paper board useful for forming a paper box for wrapping refrigerated meat which comprises: single or multi-ply paper board having a thickness of 20/100 - 65/100 mm, a degree of sizing of 900 - 4,200 seconds, degree of cobb water absorption of less than 32 g/m2, which is embossed with rugose patterns having a length of 1 - 8 mm with a depth of 40 - 130% of the thickness of the paper, at an angle of 10* - 45* with respect to the surface of the paper board, at intervals of 0.5 - 8 mm and at a density of 2 - 11/cm2, and having a water resistance of 40 - 350 g/m2 at the rugose surface, an air permeability of 200 - 4,500 sec/100 cc and a bursting strength after embossing of 3.5 - 14 kg/cm2 and having fine cracking in the water resistant coating at the rugose surface.
 5. The paper board of claim 4, wherein said rugose patterns are in the form of semi-elliptic and/or spherical recesses, said recesses being arranged in a zig-zag manner.
 6. The paper board of claim 4, wherein the peripheral edges and the rugose patterns are connected by linear to non-linear recessed grooves having a depth of from 3/100 mm to 65/100 mm. 